Mungbean Genotypes Research Articles

Scanning Electron Microscopy and Morpho-Physiological Features Imparting Differential Tolerance to Pre-harvest Sprouting (PHS) in Mungbean [Vigna radiata (L.) Wilczek

Background: In mungbean crop, the yield gap in many high yielding varieties is mainly due to lack of resistance to pre-harvest sprouting and wetting due to rains at physiological maturity or just before harvesting. Prevention of pre-harvest sprouting damage forms the most important challenge in mungbean since it has been identified as the crucial constraint for improving seed yield and quality seed. With the above perspective, the present study is aimed to identify morpho-physiological features responsible for pre-harvest sprouting and to reveal ultra structural architecture of pod and seeds of mungbean genotypes, imparting susceptibility or tolerance to pre-harvest sprouting. Methods: Four mungbean genotypes viz. ML 267 and MGG 295 (susceptible) and LGG 450 and K 851 (tolerant) were used to study the details of morpho-physiological characters such as: layers and thickness of podwall, seed coat, their external surface and internal structures of seed using scanning electron microscopy. The quantity of water accumulated, rate of moisture absorption, speed, path and pattern of water movement across the podwall and seed coat including locular space, cotyledonary area and embryonic region were studied using I2-KI treated water in time course studies on water pathway. Result: The ultrastructural architecture of pod, morpho-physiological features endowed with differential biomolecular alignment together determine the trait of tolerance or susceptibility to pre-harvest sprouting in mungbean genotypes.

Assessment of Genetic Divergence for Hardseededness with Field Emergence and Storage Duration in Mungbean Genotypes [Vigna radiata (L.) Wilczek

Hardseededness in legume crops induces uneven germination or non-synchronous seedling emergence leading to poor and un-uniform plant establishment and uneven maturity, which ultimately reduces the seed yield. An experiment was conducted with 51 mungbean genotypes to assess the influence of hard seeds on field emergence and also to know the effect of storage period on the occurrence of hard seeds. The standard germination test was performed with freshly harvested seeds and also with the seeds after 18 months of ambient storage. The results indicated that percent hard seeds varied significantly across the genotypes. The percent hard seeds showed significant negative correlation with percent normal seedlings and field emergence. More interestingly, the average per cent hard seeds decreased to 5.5% in stored seeds from 18.1% in the fresh seeds. A reduction in seed hardness following storage of 18 months under ambient conditions was recorded in the identified hardseeded genotypes indicating the possibility of increased field emergence using stored seeds for sowing.

Identification of mung bean germplasm for resistance against Cercospora canescens and to study the association of biochemical parameters with defense mechanisms

AbstractSizable loss in crop yields resulting from Cercospora leaf spot (CLS), caused by Cercospora canescens and is a major disease in mung bean [Vigna radiata (L.) R. Wilczek] crops, demands a thorough evaluation of various parameters dealing with the infection. Determination of components for CLS resistance is associated with leaf spot intensity in the field, which is estimated from the area under the disease progress curve (AUDPC). The present study showed that out of 261 genotypes screened in the field for CLS, 88, 89, 51 and, 33 genotypes were found to be resistant, moderately resistant, moderately susceptible, and susceptible, respectively, on the basis of the AUDPC values. Further, five resistant and five susceptible genotypes were selected from the screened genotypes for bioassay analysis and were subjected to artificial inoculation with three different isolates of Cercospora canescens to study the effectiveness in polyhouse. The morphological data along with disease incidence, chlorophyll content, proline content, phenol content and enzymatic activities of phenylalanine ammonia‐lyase (PAL), peroxidase (POX), and superoxide dismutase (SOD) were estimated. The findings showed that there was a significant increase in the enzymatic activities, total phenol, and proline contents in inoculated resistant and susceptible genotypes vs. control (without inoculation). However, the total chlorophyll content reduced in both resistant and susceptible genotypes after inoculation. Moreover, higher enzyme activities were marked in the resistant genotypes than the susceptible genotypes. This study will help to identify the resistant and susceptible mung bean genotypes against Cercospora canescens for further agronomic study as well as breeding programs.

Physiological and Yield Responses of Selected Mungbean Genotypes to Terminal Drought

Extreme drought conditions have been a major limiting factor in legume production worldwide. The development of drought-resilient crops should help mitigate adverse effects of unfavorable environmental conditions such as drought; however, initial characterization is necessary to ensure that the germplasm has the essential genetic variation for drought tolerance. In this study, a field trial was conducted to characterize drought response and potential drought tolerance of 100 mungbean genotypes through the evaluation of several physiological parameters and seed yield. The genotypes were subjected to terminal drought stress before flowering (~ 30 d after planting), reducing soil moisture content (SMC) from 25.0–30.0% to 13.0–15.0% during treatment imposition. Significant differences were observed between mungbean genotypes for total chlorophyll content (Chl), total scavenging activity (SA), electrolyte leakage (EC), and chlorophyll fluorescence (Fv/Fm) during drought. Furthermore, by transforming each physiological parameter into principal components (PCs) via principal component analysis (PCA), five distinct clusters were generated. Based on their physiological response and seed yield, Clusters I and II were identified as potential drought susceptible group, Cluster III was moderately susceptible, and Clusters IV and V were identified as the potential drought-tolerant group. Correlation analysis and PCA also demonstrated the significant relationship among several key traits for drought tolerance such as chlorophyll content, electrolyte leakage, and antioxidant scavenging to chlorophyll fluorescence – suggesting the suitability of fluorescence parameter in mungbean mass screening for drought tolerance. Although weak correlation between physiological parameters to seed yield was present (0.3 <│r│< 0.5), correlations among each physiological parameter were moderately strong (0.5 <│r│< 0.7). The findings suggest that a physiological characterization during initial screening for drought tolerance was an effective approach in identifying possible sources of drought tolerance traits complementary with yield- related traits. The evaluation of chlorophyll fluorescence, scavenging activity, electrolyte leakage, and chlorophyll content was enough to differentiate and characterize the drought response of several mungbean genotypes and will be vital in the development of climate-resilient crops.

绿豆种质资源苗期耐盐性鉴定及耐盐种质筛选

<p id="C3">Soil salinization has become one of the important factors affecting agricultural production in China. It is of great significance to screen germplasm resources of mungbean [<italic>Vigna radiate</italic> (L.) Wilczek] for the utilization of salinized land. In the present study, the seedlings of 346 domestic and foreign collections of mungbean were exposed to 150 mmol L ^-1 NaCl. To evaluate the salt-tolerance of different mungbean genotypes at seedling stage, 12 indicators were calculated, including plant height, fresh weight of above-ground part, fresh weight of root, dry weight of above-ground part, dry root weight, root length, and root volume. Salt tolerance of each sample was comprehensively evaluated and classified by principal component analysis, membership function analysis, salt tolerance comprehensive evaluation, and cluster analysis; and the regression equation of salt tolerance prediction was established by stepwise regression analysis. The results revealed that there were significant differences between treatment group and control group in each trait evaluation index, and the salt tolerance coefficients of the 12 indicators were correlated to some content. Combining the classification of salt damage symptoms and the comprehensive evaluation results of salt tolerance, 26 mungbean germplasms with high salt tolerance, 65 germplasms with high salt tolerance, 74 germplasms with salt sensitive, and 18 germplasms with extremely salt sensitive were selected at seedling stage. Among them, 10 varieties such as C04125 from Jiangxi and C06310 from the Philippines had the strongest salt tolerance, which could be used as excellent resources for mungbean salt tolerance breeding. Above-ground fresh weight, root fresh weight, root dry weight, root length, root volume, and root branch number could be used to predict salt tolerance of mungbean at seedling stage.

Dynamic Transcriptome Profiling of Mungbean Genotypes Unveil the Genes Respond to the Infection of Mungbean Yellow Mosaic Virus.

Yellow mosaic disease (YMD), incited by mungbean yellow mosaic virus (MYMV), is a primary viral disease that reduces mungbean production in South Asia, especially in India. There is no detailed knowledge regarding the genes and molecular mechanisms conferring resistance of mungbean to MYMV. Therefore, disclosing the genetic and molecular bases related to MYMV resistance helps to develop the mungbean genotypes with MYMV resistance. In this study, transcriptomes of mungbean genotypes, VGGRU-1 (resistant) and VRM (Gg) 1 (susceptible) infected with MYMV were compared to those of uninfected controls. The number of differentially expressed genes (DEGs) in the resistant and susceptible genotypes was 896 and 506, respectively. Among them, 275 DEGs were common between the resistant and susceptible genotypes. Functional annotation of DEGs revealed that the DEGs belonged to the following categories defense and pathogenesis, receptor-like kinases; serine/threonine protein kinases, hormone signaling, transcription factors, and chaperons, and secondary metabolites. Further, we have confirmed the expression pattern of several DEGs by quantitative real-time PCR (qRT-PCR) analysis. Collectively, the information obtained in this study unveils the new insights into characterizing the MYMV resistance and paved the way for breeding MYMV resistant mungbean in the future.

Dissecting the Root Phenotypic and Genotypic Variability of the Iowa Mung Bean Diversity Panel.

Mung bean [Vigna radiata (L.) Wilczek] is a drought-tolerant, short-duration crop, and a rich source of protein and other valuable minerals, vitamins, and antioxidants. The main objectives of this research were (1) to study the root traits related with the phenotypic and genetic diversity of 375 mung bean genotypes of the Iowa (IA) diversity panel and (2) to conduct genome-wide association studies of root-related traits using the Automated Root Image Analysis (ARIA) software. We collected over 9,000 digital images at three-time points (days 12, 15, and 18 after germination). A broad sense heritability for days 15 (0.22–0.73) and 18 (0.23–0.87) was higher than that for day 12 (0.24–0.51). We also reported root ideotype classification, i.e., PI425425 (India), PI425045 (Philippines), PI425551 (Korea), PI264686 (Philippines), and PI425085 (Sri Lanka) that emerged as the top five in the topsoil foraging category, while PI425594 (unknown origin), PI425599 (Thailand), PI425610 (Afghanistan), PI425485 (India), and AVMU0201 (Taiwan) were top five in the drought-tolerant and nutrient uptake “steep, cheap, and deep” ideotype. We identified promising genotypes that can help diversify the gene pool of mung bean breeding stocks and will be useful for further field testing. Using association studies, we identified markers showing significant associations with the lateral root angle (LRA) on chromosomes 2, 6, 7, and 11, length distribution (LED) on chromosome 8, and total root length-growth rate (TRL_GR), volume (VOL), and total dry weight (TDW) on chromosomes 3 and 5. We discussed genes that are potential candidates from these regions. We reported beta-galactosidase 3 associated with the LRA, which has previously been implicated in the adventitious root development via transcriptomic studies in mung bean. Results from this work on the phenotypic characterization, root-based ideotype categories, and significant molecular markers associated with important traits will be useful for the marker-assisted selection and mung bean improvement through breeding.

Transcriptome and methylome changes in two contrasting mungbean genotypes in response to drought stress

BackgroundDue to drought stress, the growth, distribution, and production of mungbean is severely restricted. Previous study combining physiological and transcriptomic data indicated different genotypes of mungbean exhibited variable responses when exposed to drought stress. Aside from the genetic variation, the modifications of environmentally induced epigenetics alterations on mungbean drought-stress responses were still elusive.ResultsIn this study, firstly, we compared the drought tolerance capacity at seedling stage by detecting physiological parameters in two contrasting genotypes wild mungbean 61 and cultivar 70 in response to drought stress. We found that wild mungbean 61 showed lower level of MDA and higher levels of POD and CAT, suggesting wild mungbean 61 exhibited stronger drought resistance. Transcriptomic analysis indicated totally 2859 differentially expressed genes (DEGs) were detected when 70 compared with 61 (C70 vs C61), and the number increased to 3121 in the comparison of drought-treated 70 compared with drought-treated 61 (D70 vs D61). In addition, when drought-treated 61 and 70 were compared with their controls, the DEGs were 1117 and 185 respectively, with more down-regulated DEGs than up-regulated in D61 vs C61, which was opposite in D70 vs C70. Interestingly, corresponding to this, after drought stress, more hypermethylated differentially methylated regions (DMRs) in 61 were detected and more hypomethylated DMRs in 70 were detected. Further analysis suggested that the main variations between 61 and 70 existed in CHH methylation in promoter. Moreover, the preference of methylation status alterations in D61 vs C61 and D70 vs C70 also fell in CHH sequence context. Further analysis of the correlation between DMRs and DEGs indicated in both D61 vs C61 and D70 vs C70, the DMRs in gene body was significantly negatively correlated with DEGs.ConclusionsThe physiological parameters in this research suggested that wild mungbean 61 was more resistant to drought stress, with more hypermethylated DMRs and less hypomethylated DMRs after drought stress, corresponding to more down-regulated DEGs than up-regulated DEGs. Among the three DNA methylation contexts CG, CHG, and CHH, asymmetric CHH contexts were more dynamic and prone to be altered by drought stress and genotypic variations.

Association Mapping for Yield Attributing Traits and Yellow Mosaic Disease Resistance in Mung Bean [Vigna radiata (L.) Wilczek

Mung bean [Vigna radiata (L.) Wilczek] is an important short-duration grain legume widely known for its nutritional, soil ameliorative, and cropping system intensification properties. This study aims at evaluating genetic diversity among mung bean genotypes and detecting genomic regions associated with various yield attributing traits and yellow mosaic disease (YMD) resistance by association mapping. A panel of 80 cultivars and advanced breeding lines was evaluated for 10 yield-related and YMD resistance traits during kharif (monsoon) and summer seasons of 2018–2019 and 2019–2020. A total of 164 genome-wide simple sequence repeat (SSR) markers were initially screened, out of which 89 were found polymorphic which generated 317 polymorphic alleles with an average of 3.56 alleles per SSR locus. The number of alleles at each locus varied from 2 to 7. The population genetic structure analysis grouped different genotypes in three major clusters and three genetically distinct subpopulations (SPs) (i.e., SP-1, SP-2, and SP-3) with one admixture subpopulation (SP-4). Both cluster and population genetic structure analysis categorized the advanced mung bean genotypes in a single group/SP and the released varieties in other groups/SPs, suggesting that the studied genotypes may have common ancestral history at some level. The population genetic structure was also in agreement with the genetic diversity analysis. The estimate of the average degree of linkage disequilibrium (LD) present at the genome level in 80 mung bean genotypes unveiled significant LD blocks. Over the four seasons, 10 marker-trait associations were observed significant for YMD and four seed yield (SY)-related traits viz., days to flowering, days to maturity, plant height, and number of pods per plant using the mixed linear model (MLM) method. These associations may be useful for marker-assisted mung bean yield improvement programs and YMD resistance.

New High Yielding Mung Bean Variety Phule Chetak for Maharashtra

Background: Mung bean is one of the important pulse crop requiring low inputs. The productivity of kharif mung bean is very low. The present improved varieties have lower yield potential and disease susceptibility. There is a need to develop high yielding varieties combined with early to mid synchronous maturity, better quality and resistance/tolerance to major pests and diseases. Methods: The green gram var. Phule Chetak was developed by pedigree selection method from a cross between SML-668 X Naval at Oilseeds Research Station, MPKV, Jalgaon. It was tested over several locations and environments for its stability performance. Result: The results indicated a significant improvement in yield level under field conditions. The new variety Phule Chetak reported an average yield of 1003 kg/ha which is 26.96%, 36.46%, 29.42%, 21.72%, 17.58% and 13.21 per cent higher than the check varieties Vaibhav, BPMR-145, AKM-8802, BM-2002-1, BM-2003-2 and Utkarsha respectively. It is bold seeded having early maturity, moderately resistant to major diseases like powdery mildew, mungbean yellow mosaic virus under field conditions. Considering its consistent performance, the mung bean genotype PM-707-5 has been released for cultivation in the kharif season for Maharashtra under the name of Phule Chetak in Joint Agresco during 29-30 October, 2020 held at Dr PDKV, Akola.

English

The damaging potential of Alternaria alternata on different mungbean genotypes was accessed and its management was done under in vitro and in vivo conditions through suitable fungicides. Seeds of fifty different mungbean genotypes were sown in lines. There were fifteen replications for each line. The data on disease incidence and percent disease intensity were accessed on all the genotypes. Infection was observed on all genotypes, none of them were found to be immune. Fourteen lines were found to be the most susceptible (14114, 14117, 14128, 14198, 14203, 14205, 14250, 14265, 14266, 14295, 14305, 14306, 14368, 14438). Infection was observed on all genotypes, none of them were found to be immune. The maximum PDI (Percent Disease Intensity) was recorded 35.30% while minimum was 2.43%. For detached leaf assay, the conidial suspension of 105 conidia/mLwas prepared and sprayed on detached leaves. The results revealed that maximum infection percentage was observed in 14306, 14198 genotypes while minimum was observed in 14128, 14203. The lesion area was found to be maximum in 14306, 14198 (0.23, 0.22) while minimum in 14128 (0.12) respectively. For management experiments, different fungicides; Propiconazole (Tilt), Propineb (Antracol), Difenconazole (Score), Thiophanate methyl (Topsin M), Mancozeb (Dithane M45) were tested under in vitro and in vivo conditions. Significant decrease in mycelial growth with the increase in concentration of fungicides was observed. Percent inhibition of mycelial growth was maximum in Propiconazole at its highest concentration (1000 ppm) under in vitro conditions. A significant decline in disease incidence was observed as compared to control treatment. The minimum percent disease incidence was recorded in Propiconazole (10.34) with PDC (67.31) while the maximum percent disease incidence was observed in Thiophanate methyl (25.46). So, Propiconazole could be used successfully for the management of A. alternata under field conditions.

Evaluation of P1, P2, F1, F2, B1 and B2 generations of LM 95 × EC 362096 cross of mung bean for yield and yield attributes along with water use efficiency and heat stress tolerance related traits using generation mean analysis

In mung bean, limited work has been done on yield attributes along with water use efficiency (WUE) and heat stress tolerance related traits. Realizing the significance of drought and heat stress on yield components, there is need to enhance the genetic potential of mung bean genotypes with high yield and drought and heat stress tolerance. The experimental material comprising six populations viz P1, P2, F1, F2, B1 and B2 of the cross LM 95 × EC 362096 was grown at the dryland farm of SV Agricultural College, Tirupati, Andhra Pradesh during rabi 2017 in compact family block design with two replications. The mean data obtained from six generations (P1, P2, F1, F2, B1 and B2) of selected superior cross LM 95 × EC 362096 for yield, yield components, WUE and heat stress tolerance related traits were subjected to generation mean analysis. Partitioning of generation means into six components revealed that the component mean [m] was positive and highly significant for all the traits. The results of scaling tests revealed that additive-dominance model was not sufficient to explain the inheritance of the characters studied. The inadequacy of additive-dominance model suggested the possible involvement of di-genic or higher order epistatic gene action in the expression of all the traits. It also indicated the presence of positively significant proportion of epistatic {[i], [j] and [l]} effects besides main {[d] and [h]} effects for yield, yield attributes, WUE and heat stress tolerance related traits. The findings divulged that both additive and the dominance components were important in the inheritance of yield, WUE and heat stress tolerance related components.

Screening Mungbean Accessions for Susceptibility to Soybean Fungal Diseases in Iowa

United States’ sales of mungbean ( Vigna radiata L. Wilczek) products and other plant-based protein sources exceeded $1 billion in 2020. Most mungbean consumed in the United States is imported, but it has considerable potential as a domestic crop. Its heat and drought tolerance give U.S. farmers an alternative to soybean and corn crop rotation. Mungbean is a 60- to 90-day crop with similar equipment needs, chemical inputs, and storage requirements to those of soybean and has a developed market. Its vulnerability to diseases in the United States is unknown. Thus, we compared the susceptibility of 10 mungbean genotypes to 8 soybean diseases in the lab. We also monitored disease occurrence in sentinel field plots in Iowa. Mungbean accessions showed a wide range of susceptibility to Cercospora kikuchii, Colletotrichum gloeosporioides, Diaporthe caulivora, Fusarium oxysporum, F. virguliforme, Macrophomina phaseolina, Pythium sylvaticum, and Sclerotinia sclerotiorum. Symptoms of frogeye leaf spot, sudden death syndrome, and Rhizoctonia root and crown rot, common soybean diseases, were observed on mungbean in the field; isolates were identified as Cercospora sojina, F. virguliforme, and Rhizoctonia solani, and Koch's postulates were conducted. C. sojina and F. virguliforme are newly reported as causing disease in field-grown mungbean.

Screening of mungbean genotypes for resistance against thrips, Megalurothrips distalis (Karny)

The data obtained from this study showed that the overall mean population of thrips per plant was minimum in the genotype IC-329039 followed by IC-325782, while maximum population of thrips was recorded in IC-103862 followed by IC-39446. The genotypes which were grouped under resistance category in both the seasons were selected for further evaluation to develop desirable varieties.

Canopy and reproductive development in mungbean (

Context Mungbean (Vigna radiata (L.) Wilczek) is an important grain legume for food, feed, and green manure. Mungbean yield is highly variable due to fluctuating temperature and unpredictable rainfall. Aims To improve yield stability, it is critical to utilise a model that can simulate mungbean phenology, biomass, and yield accurately. Methods A thorough understanding of the physiological determinants of growth and yield is required to advance existing mungbean crop modelling capability. Currently, there is limited understanding of the physiological determinants of canopy and reproductive development and their variation in mungbean germplasm. Two experiments (controlled and field environments) were conducted at Gatton, Queensland, in 2018–19. Six Australian mungbean genotypes and one black gram (Vigna mungo L.) were grown under non-limiting conditions. Plant phenotypic traits (canopy development, time to first, 50% flowering, duration of flowering and podding, flower appearance, pod addition rates) were recorded. Key results Genotypes M10403 and Satin II had significantly higher leaf appearance rate (LAR). Genotypes with a greater LAR had higher number of leaves but lower individual leaf area. Genotypes varied significantly in time to first and 50% flowering, with Onyx-AU (black gram) and Celera II-AU flowering earliest. Flowering and podding rates, and duration of these phenological phases varied among genotypes. Total plant leaf area (TPLA) approached its maximum at mid-podding stage. Implications This study quantified the key phenotypic and physiological relationships associated with canopy and reproductive development, critical for the improvement of mungbean crop modelling required to accurately simulate growth and development and inform possible canopy constraints that are limiting mungbean productivity.

Response of mungbean to foliar application of nitrogen and micronutrients during reproductive stages

An experiment was conducted at the pot yard of Bangladesh Institute of Nuclear Agriculture, Mymensingh during the period from February to May 2017 to investigate the effect of foliar application of nitrogen and micronutrients on crop characters, yield attributes and yield of two mungbean genotypes. The experiment comprised four levels of nutrients foliar application like, i) T1 = Control; ii) T2 = Foliar application of urea at the rate of 1.5% four times from flowering start to pod development stage with an interval of 4 days; iii) T3 = T2 + 0.1% micronutrients (B, Mo, Zn, Mn, Ca, Fe, Cu) four times from flowering start to pod development stage with an interval of 4 days and iv); T4 = T3 + side dressing (soil application) of 1.5% N and 0.1% micronutrients solution four times from flowering start to pod development stage with an interval of 4 days. The genotypes were Binamoog-6 and Binamoog-7. Results revealed that morphological (plant height, branch and leaf number, leaf area plant-1), physiological (total dry mass plant-1, specific leaf weight, chlorophyll), yield attributes (number of pods plant-1, pod length, single pod weight, number of seeds pod-1 and 100-seed weight) and yield increased in foliar nutrients applied plants over control but the increment was greater in T2 and T3 than the T4 treatment. The highest plant height, branch and leaf number, leaf area, total dry mass, pod number, pod length, 100-seed weight and seed yield were recorded in T2 followed by T3 with same statistical rank (in most cases). The lowest morpho-physiological, yield attributes and yield were recorded in T1 (control) plants. Binamoog-7 was superior in most of plant parameters and yield compared to Binamoog-6.

Physiochemical Changes of Mung Bean [Vigna radiata (L.) R. Wilczek] in Responses to Varying Irrigation Regimes

Mungbean is one of the most powerful pulses providing substantial protein for human diets and fixing N to the soil, improving nutritional food security and agricultural sustainability. The production of summer mungbean in the tropics and subtropics is adversely affected by drought due to water scarcity caused by various factors as well as lack of rainfall. Irrigation at different growth phases is not a suitable solution. An environmentally friendly and economically viable answer is a convenient irrigation management option that will be available to farmers together with drought-tolerant genotypes. The study considered to determine the effect of differences between drought-tolerant and drought susceptible genotypes on water productivity response and physiological traits in mung beans. To quantify seed yield-related to irrigation at different growth stages eventually to quickly determine the most appropriate irrigation stage. One water stress tolerant mung bean genotype (BMX-08010-2) and one sensitive genotype (BARI Mung-1) were grown in the field with four different irrigation schedules along with water stress conditions (no irrigation) under rain shelter at Regional Agricultural Research Station, BARI, Ishwardi, Pabna, Bangladesh. The experiment was laid out in split plots with three replications, with irrigation schedules assigned in the main plot and mung bean genotypes assigned in the side plots. Water use efficiency ranged from 3.79 to 4.68 kg ha−1 mm−1 depending on irrigation regime, and mung bean seed yield of mung bean Water stress decreased plant water status, photosynthetic pigment and membrane stability index, and increased proline soluble sugar content. Treatments that received irrigation during two or three phases (I3 or I4) gave significantly higher yields than those that received irrigation during only one stage (I1 and I2) with the lowest yield. While the yield obtained ranged between 1145.44 kg ha−1 with seasonal irrigation of 277 mm (I4) and 555.14 kg ha−1 without irrigation (I0). The flowering stage (I3) was recorded as the most sensitive growth stage with an 18.15% yield reduction compared to the treatment with triple irrigation (I4). Also, depending on the irrigation sources, at least two irrigation phases should be provided at the triple leaf stage (I2, i.e., 20 DAS) and at the flowering stage (I3, i.e., 35 DAS) to achieve the highest yield. Genotypes that maintained the higher performance of physicochemical traits under water stress provided higher seed yield and promoted drought tolerance. Therefore, these parameters can be used as physiological and biochemical markers to identify and develop superior genotypes suitable for drought-prone environments.

Assessment of molecular diversity among mungbean [Vigna radiata (L.) Wilczek] genotypes using EST-SSR marker

Genetic diversity can be assessed through molecular markers at the DNA level because of their abundance as compared to morphological characters and independence of environmental influences. By using expressed sequence tag-simple sequence repeat (EST-SSR) markers molecular diversity of thirty mungbean genotypes was analysed at S.D.A.U., Sardarkrushinagar (Gujarat) during 2019. DNA was extracted using CTAB method. Total 21 EST-SSR primers were screened across all the genotypes. Amplification of eleven alleles were done and high polymorphism (100.00%) was found from 5 EST-SSRs primers (MB21347, MB11596, MB34120, MB24478 and MB15212). Each locus has 2 to 3 alleles, with 2.2 average alleles per locus. The range pf PIC (Polymorphic Information Content) was 0.204 to 0.580, with 0.348 average. Similarity indices derived from Jaccard’s similarity co-efficient were estimated on the basis of five EST-SSR primers ranged from 0.091 to 1.00. Genotype, LM-584 and PIMS 1 showed minimum similarity. Two main clusters and six sub-clusters were formed in a dendrogram prepared using UPGMA analysis. PCA and PCoA plot based on EST-SSR primer study was constructed and genotypes have been distributed into four major groups in each method. Overall results suggested that EST-SSR can be a great tool to explore genetic diversity in mungbean.

Agromorphological Evaluation of 44 lines of Mung Bean (Vigna radiata (L.) Wilczek) Introduced in Burkina Faso

Mung bean (Vigna radiata L. Wilczek) is an important annual legume which is well suited to dry areas, like Burkina Faso where it is still an orphan legume. The present study was conducted to evaluate 44 mung bean genotypes introduced in Burkina Faso and to determine genetic diversity in this collection using both quantitative and qualitative traits. A field experiment was conducted in an augmented bloc design with three blocks and an extraearly maturing cowpea variety as check. Data were recorded on six (06) quantitative traits and seven (07) qualitative traits. For qualitative traits, diversity was revealed in four parameters including hypocotyl’s color, seed coat color, pods and stem pubescence. Significant genetic variability was revealed among genotypes for all the quantitative characters. Phenotypic coefficient of variation (PCV) was higher than Genotypic coefficient of variation (GCV) for all characters studied indicating the influence of environmental effect on the characters. The GCV and PCV estimates were high for number of pods per plant followed by plant height and hundred seeds weigh. The high heritability coupled with high genetic advanced as percent of mean observed for these traits suggest an important genetic gain in genetic improvement for these characters. The genetic diversity observed was grouped into five clusters. Mungbean lines were grouped into four clusters and the cowpea variety used as check crop in this trial was clustered apart. This gbiodiversityenetic diversity, both qualitatively and quantitatively, will help enrich local in terms of legumes in general and mung bean in particular and constitutes an important basis for a future mungbean breeding program.

Selection for earliness and seed yield in Mung bean accessions using REML/BLUP

Abstract The objective of this work was to select early maturing and high yielding mung bean (Vigna radiata) genotypes for savanna and rainforest conditions in Nigeria. Twenty mung bean genotypes were evaluated, in 2019 and 2020, in the following agroecological zones of Southwestern Nigeria: Rainforest, Derived Savanna, and Southern Guinea Savanna, totaling six environments. The experiment was carried out in a randomized complete block design with three replicates. The restricted maximum likelihood (REML)/best linear unbiased prediction (BLUP) mixed model was used. The magnitude of the phenotypic coefficient of variation was higher than that of the genotypic coefficient of variation for all agronomic characters measured. A high heritability estimate was recorded for first flowering (87%), followed by pod length (85%), number of seeds per pod (79%), and 50% flowering (55%). However, a low heritability was observed for seed yield per hectare (23%). The selective accuracy was 0.5 for yield, which is considered moderate, and ranged from 0.7 to 0.9 for the other characters. A yield of 1,472.93 kg ha-1 was obtained across the six environments. Nine promising genotypes (TVr-45, TVr-98, TVr-64, TVr-102, TVr-86, TVr-106, TVr-9, TVr-95, and TVr-33) were identified. Therefore, these genotypes are suitable and adapted for cultivation in the agroecological zones of Southwestern Nigeria.